1. Field of the Invention
The present invention concerns a novel process for adjusting the amine load upon an absorption column intended for the disulfuration of gas, taking into account the absorption rate of the gas to be eliminated on the amine. It also concerns a device which reduces to practice the process and in particular the photometric cell that allows measurements.
2. Description of the Prior Art
Scrubbing using amine, of gas containing hydrogen sulfide is well known to the man skilled in the art. According to this process, the gas to be scrubbed is injected into the bottom of an absorption column, in which it is contacted at counter-current with an amine solution. The scrubbed gas is recovered at the head of the column and the amine loaded with hydrogen sulfide exits at the bottom of the column, in order to be regenerated and reinjected into the absorption column.
The problem that arises is that of controlling the amine flow-rate taking into account operating conditions. It is possible, as disclosed in French Pat. No. 2,141,413, to control the mass flow-rate of the amine solution to the mass flow-rate of the gas to be scrubbed. It is also possible, as disclosed in U.S. Pat. No. 3,288,706 to analyze the gas at the output of the absorption column (once scrubbed) or the saturated amine at the bottom of the column.
These different control and adjustment methods present the principal drawback of being based upon parameters that are external to the column, namely:
in particular for the first above-mentioned patent, the process is based on elements existing prior to the reaction per se and thus is not able to take into account the behavior per se of the reaction;
for the second above-mentioned patent, the process is based on observing subsequently the result of the reaction and thus on reacting with a lapse of time.
These parameters do not take into account an eventual loss of adjustment or an overload on the column, due to a discrepancy of the measurements with respect to the absorption reactions and/or to a lack of precision and to the variable response time of the equipment.